Not quite. Portrait of Ruin takes place in 1944 during World War II, which is pretty close to modern times all things considered.
One thing that's interesting to me is that Castlevania and DMC are owned by different people; the former is owned by Konami and the latter is owned by Capcom. I'm not saying that collaboration between studios is totally out of the question, especially in Capcom's case considering some of their biggest games are crossovers. I think it's actually kinda cool that they're allowing this.